JP7823077B2 - antibacterial compounds - Google Patents

Description

The present invention relates to antibacterial compounds as defined herein, pharmaceutical compositions containing the compounds, and the use of the compounds and pharmaceutical compositions containing the compounds in the treatment of bacterial infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriaceae, particularly Gram-negative bacteria of the order Enterobacteriaceae that have acquired resistance to existing antibiotics.

New antibacterial compounds are needed to combat the emergence of bacterial pathogens with resistance to existing antibacterial compounds. The increasing incidence of bacterial resistance to existing antibiotics threatens to lead to multidrug resistance becoming common among many bacterial pathogens, significantly increasing the burden of common infections on society. For example, antibiotic-resistant strains of ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species), such as carbapenem-resistant Enterobacteriaceae (CRE), multidrug-resistant (MDR) Acinetobacter, MDR Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), are included in the list of antibiotic-resistant microorganisms identified as posing an urgent or serious threat to human health. Other notable antibiotic-resistant pathogens include the gram-positive anaerobic bacterium Clostridium difficile, drug-resistant Neisseria gonorrhoeae, and drug-resistant Mycobacterium tuberculosis.

Specifically, resistance of Gram-negative bacteria, particularly those of the order Enterobacteriaceae, to existing antibiotic agents, such as carbapenem (β-lactam) antibiotics, is increasing. Antibiotic-resistant Gram-negative Enterobacteriaceae strains, such as Escherichia coli NDM-1 (New Delhi metallo-β-lactamase) and carbapenemase-producing Enterobacterales bacteria, such as Klebsiella pneumoniae, are difficult to treat, are becoming increasingly prevalent, and are becoming increasingly virulent. Furthermore, newly emerging hypervirulent, multidrug-resistant, and highly infectious strains of carbapenem-resistant Klebsiella pneumoniae, such as the ST11 carbapenem-resistant hypervirulent Klebsiella pneumoniae strain, have been identified and are associated with deadly outbreaks. Such strains are resistant to historical and currently recommended antibiotics and are currently a major public health concern worldwide.

Currently, Enterobacteriaceae infections suspected to be carbapenem-resistant Enterobacteriaceae (CRE) are commonly treated with broad-spectrum agents. Such treatment typically consists of a combination of a β-lactam antibiotic and a β-lactamase inhibitor (BL/BLI) or the antibiotic of last resort, colistin. BL/BLI combinations are effective in the short term but are predicted to eventually succumb to the bacteria's pre-existing resistance mechanisms. Furthermore, these broad-spectrum agents are not active against all Ambler β-lactamase classes and lack activity against metallo-β-lactamases, which confer resistance to a broad range of β-lactam antibiotics, including carbapenems.

Therefore, there is a need for new antibacterial compounds that can provide reliable and effective treatment for infections caused by, or diseases exacerbated by, Gram-negative bacteria of the order Enterobacteriaceae that are resistant to known antibiotics, such as carbapenems and other β-lactams, or that are associated with multidrug-resistant infectious agents. Furthermore, there is a need to provide antibiotic formulations that can avoid or reduce the side effects associated with known antibacterial compounds.

Aspects of the present invention aim to provide solutions to the above-mentioned problems and other problems.

According to a first aspect of the present invention, compound (I):

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

According to a second aspect of the present invention, there is provided a compound (I) for use in the treatment or prevention of infection with, or a disease caused or exacerbated by, a gram-negative bacterium of the order Enterobacteriaceae and/or a gram-negative bacterium of the genus Haemophilus:

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

According to a third aspect of the present invention, there is provided a compound (I) for use in a method for treating infection with, or a disease caused or exacerbated by, a gram-negative bacterium of the order Enterobacteriaceae and/or a gram-negative bacterium of the genus Haemophilus:

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

According to a fourth aspect of the present invention, there is provided a compound (I) for use in the manufacture of a medicament for use in treating infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus:

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

According to a further aspect of the present invention, there is provided a method for treating an infection caused by, or a disease exacerbated by, a gram-negative bacterium of the order Enterobacteriaceae and/or a gram-negative bacterium of the genus Haemophilus in a subject in need thereof, comprising administering an effective amount of compound (I):

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof to said subject.

Compound (I) has bactericidal activity against gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus, and can be used in the treatment or prevention of infections caused by gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus, or diseases caused or exacerbated by them.

According to a further aspect of the present invention, compound (I) is provided for use in the treatment of infection with, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus:

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

According to a further aspect of the present invention, compound (I):

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof to inhibit the growth of Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus in vitro.

According to a further aspect of the present invention, compound (I): is formulated together with a pharmaceutically acceptable excipient or carrier.

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

According to a further aspect of the present invention, compound (I):

or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, and a pharmaceutically acceptable excipient or carrier.

According to a further aspect of the present invention, there is provided a pharmaceutical composition for use in treating infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, comprising compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, and a pharmaceutically acceptable excipient or carrier, wherein compound (I) is

The present invention provides a pharmaceutical composition comprising:

According to a further aspect of the present invention, there is provided a pharmaceutical composition for use in treating infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, comprising compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, and a pharmaceutically acceptable excipient or carrier, wherein compound (I) is

wherein the pharmaceutical composition is administered by intravenous infusion at a dose of 50 to 6000 mg per day of Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

Definitions: As used herein, the term "disease" or "bacterial disease" is used to define an abnormal condition that impairs physiological function and is associated with specific symptoms. The term is used broadly to encompass any disorder, disease, abnormality, lesion, disorder, condition, or syndrome in which physiological function is impaired, regardless of the nature of the etiology (or indeed whether an etiological basis for the disease has been established). Thus, the term encompasses conditions resulting from trauma, injury, surgery, radiological ablation, poisoning, or nutritional deficiency. The term refers to any disease involving (e.g., caused by, exacerbated by, associated with, or characterized by) bacteria residing and/or replicating within the body and/or cells of a subject. Thus, the term includes diseases caused or exacerbated by bacterial toxins (sometimes referred to herein as "bacterial poisoning").

As used herein, the terms "infection" or "bacterial infection" are used to define a condition in which a subject is infected with bacteria. An infection can be symptomatic or asymptomatic. If symptomatic, the subject can be identified as infected based on established diagnostic criteria. If asymptomatic, the subject can be identified as infected based on various tests, including, for example, biochemical tests, serological tests, microbial culture methods, and/or microscopy. Thus, the present invention typically finds use in treating subjects in which a bacterial infection has been diagnosed or detected.

As used herein, the terms "treatment" or "treating" refer to an intervention (e.g., administration of a drug to a subject) that cures, alleviates, or reduces the symptoms of a disease or eliminates (or reduces the effects of) its cause (e.g., a causative bacterium). In this context, the term is used synonymously with the term "therapy." Thus, treatment of infections according to the present invention can be characterized by the bactericidal action (direct or indirect) of the compounds of the present invention. Accordingly, the compounds of the present invention find use in methods of killing or preventing the growth of bacterial cells.

Furthermore, the term "treatment" or "treating" refers to an intervention (e.g., administration of a drug to a subject) that prevents or delays the onset or progression of, or reduces the incidence of (or eradicates) a disease within a treated population. In this context, the term treatment is used synonymously with the term "prophylaxis."

The term "subject" (which should be interpreted as including "individual," "animal," "patient," or "mammal," where the context allows) defines any subject for which treatment is indicated, particularly a mammalian subject. Mammalian subjects include, but are not limited to, humans, domestic animals, livestock, zoo animals, sport animals, and pet animals, such as dogs, cats, guinea pigs, rabbits, rats, mice, horses, cows, and cows; primates, such as apes, monkeys, orangutans, and chimpanzees; canines, such as dogs and wolves; felines, such as cats, lions, and tigers; equines, such as horses, donkeys, and zebras; food animals, such as cows, pigs, and sheep; ungulates, such as deer and giraffes; and rodents, such as mice, rats, hamsters, and guinea pigs. Preferably, the subject is a human.

The terms "Gram-negative bacteria" and "Gram-positive bacteria" are technical terms that define two different classes of bacteria based on certain cell wall staining characteristics.

As used herein, an "effective amount" of a compound or agent is an amount that achieves a desired pharmacological effect or therapeutic improvement without undue adverse side effects. As used herein, a "therapeutically effective amount" refers to a sufficient amount of an agent or compound being administered that relieves to some extent one or more symptoms of an infection or disease. The result can be a reduction and/or alleviation of the signs, symptoms, or causes of an infection or disease, or any other desired alteration of a biological system. A complete cure is not required for the outcome of treatment. The term "therapeutically effective amount" includes, for example, a prophylactically effective amount. It is understood that an "effective amount" or "therapeutically effective amount" can vary from subject to subject depending on the individual's age, weight, general condition, mode of administration, the condition being treated, the severity of the condition being treated, and other factors.

As used herein, a "prophylactically effective amount" refers to an amount effective, at the dosage and for the period of time necessary, to achieve the desired prophylactic result. Typically, since a prophylactic dose is used in subjects before the onset of disease or at an early stage of disease, the prophylactically effective amount will be less than the therapeutically effective amount.

The term "effective" includes beneficial effects such as additivity, synergy, reduced side effects, reduced toxicity, improved performance, reduced bacterial load during infection, or activity.

The term "pharmaceutically acceptable salt" as applied to Compound (I) of the present invention defines any organic or inorganic acid addition salt of the free base that is suitable for use in contact with the tissues of humans and animals without undue toxicity, irritation, or allergic response, and that is commensurate with a reasonable benefit/risk ratio. Suitable pharmaceutically acceptable salts are well known in the art. Examples include salts formed from inorganic acids (e.g., hydrochloric acid, hydrobromic acid, sulfuric acid, and phosphoric acid), organic carboxylic acids (e.g., acetic acid, propionic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, fumaric acid, malic acid, tartaric acid, citric acid, ascorbic acid, maleic acid, hydroxymaleic acid, dihydroxymaleic acid, benzoic acid, phenylacetic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, anthranilic acid, cinnamic acid, salicylic acid, 2-phenoxybenzoic acid, 2-acetoxybenzoic acid, and mandelic acid), and organic sulfonic acids (e.g., methanesulfonic acid and p-toluenesulfonic acid).

The term "solvate" as applied to Compound (I) of the present invention means a physical association of Compound (I) with one or more solvent molecules, whether organic or inorganic. This physical association can include hydrogen bonding. In certain instances, a solvate will be capable of isolation, for example, when one or more solvent molecules are incorporated within the crystal lattice of a crystalline solid. A solvate may contain either a stoichiometric or a non-stoichiometric amount of solvent molecules. For example, a solvate containing a non-stoichiometric amount of solvent molecules may result from partial loss of solvent from the solvate. "Solvate" encompasses both solution-phase and isolatable solvates. Exemplary solvates include hydrates, ethanolates, methanolates, isopropanolates, and the like. Methods of solvation are generally known in the art.

The term "hydrate" as applied to compound (I) of the present invention refers to compound (I) when associated with water in molecular form, i.e., where the H-OH bond is unsplit and can be represented, for example, by the formula R·H ₂ O, where R is a compound of the present invention. A given compound may form more than one hydrate, including, for example, a monohydrate (R·H ₂ O) or polyhydrate (R·nH ₂ O, where n is an integer >1), such as a dihydrate (R·2H ₂ O), a trihydrate (R·3H ₂ O), etc., or a hemihydrate, for example, R·n/2H ₂ O, R·n/3H ₂ O, R·n/4H ₂ O, etc., where n is an integer.

As used herein, the term "prodrug" as applied to compound (I) refers to a pharmacologically acceptable derivative, such as an ester, amide, or phosphate, in which the in vivo biotransformation product of the resulting derivative is an active drug as defined by the compound of formula (I). The reference by Goodman and Gilman (The Pharmacological Basis of Therapeutics, 8th ed., McGraw-HiM, Int. Ed. 1992, "Biotransformation of Drugs," pp. 13-15), which generally describes prodrugs, is incorporated herein. Prodrugs of compound (I) of the present invention are prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved to the parent compound, either by routine manipulation or in vivo. Prodrugs of the compounds of the present invention include compounds in which the amino group of compound (I) is bonded to any group that cleaves to form the free amino group when the prodrug is administered to a subject. The term includes all positional isomers thereof.

In its broadest aspect, the present invention contemplates all optical isomers of Compound (I), or pharmaceutically acceptable salts, hydrates, solvates, complexes, or prodrugs thereof.

When the stereochemical form of compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is important to pharmaceutical utility, the present invention contemplates the use of the isolated eutomer.

As used herein, the term "resistant bacterial strain" refers to a bacterial strain that has demonstrated resistance or insensitivity to one or more known antibacterial agents, particularly those widely considered standard of care in the treatment of infections caused by such strains. A "non-susceptible strain" is one in which the MIC (minimum inhibitory concentration) of a given compound or class of compounds against that strain has shifted to a value higher than the MIC for the corresponding susceptible strain. For example, a non-susceptible strain may refer to a strain that is insusceptible to β-lactam antibiotics, a strain that is insusceptible to one or more fluoroquinolones, and/or a strain that is insusceptible to one or more other antibiotics (i.e., antibiotics other than β-lactams and fluoroquinolones). In some cases, the term "resistant" may refer to a strain in which the MIC of a given compound or class of compounds against that strain has shifted to a value significantly higher than the MIC for the corresponding susceptible strain. A bacterial strain may be said to be resistant to a given antibiotic if it is inhibited in vitro by a concentration of this agent, which is associated with a high probability of treatment failure.

As used herein, the terms "multidrug-resistant" or "multidrug-resistant" refer to organisms, such as highly resistant Gram-negative bacteria (e.g., carbapenemase-producing Klebsiella pneumoniae), that exhibit in vitro and/or in vivo resistance to two or more antimicrobial agents. Such organisms may be resistant to all currently available antimicrobial agents or may remain susceptible only to older, potentially more toxic, antimicrobial agents.

As used herein, the term "hypervirulent" refers to an exceptionally virulent organism, generally as a result of the acquisition of a hypervirulence plasmid. Such organisms have the potential to cause severe disease. For completeness, "hypervirulent" refers to an organism that has the potential to cause extremely severe or deleterious effects and disease.

As used herein, the term "antibacterial treatment" refers to the treatment of an infection or disease in a subject with an antibacterial agent other than compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof. Typically, in the context of the present invention, this is with a known antibiotic or treatment method, including a carbapenem or other β-lactam antibiotic, other than compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

FIG. 1a shows the results of all 44 ligands tested in the in vitro pharmacological binding assay for Compound (I), Comparative Compound (II), and Comparative Compound (III). Same as above. Same as above. FIG. 1d shows only the results of the in vitro pharmacological binding assay for Compound (I), Comparative Compound (II) and Comparative Compound (III) that show more than 50% inhibition. FIG. 2 shows the results of evaluating Compound (I) and comparative Compound (III) in a proof-of-concept study in a mouse model for the treatment of respiratory infections caused by Gram-negative bacteria of the order Enterobacteriaceae. FIG. 3 shows the results of evaluating Compound (I) and comparative Compound (III) in a proof-of-concept study in a mouse model for the treatment of bacteremia or bloodstream infection due to Gram-negative bacteria of the order Enterobacteriaceae. FIG. 4a shows the results of evaluating compound (I) and comparative compound (III) in a proof-of-concept study in a mouse model for the treatment of urinary tract infections due to Gram-negative bacteria of the order Enterobacteriaceae. Same as above. Same as above. FIG. 5 shows the results of compound (I) being further evaluated in a proof-of-concept study in a mouse model for the treatment of respiratory infections caused by Gram-negative bacteria of the order Enterobacteriaceae. FIG. 6a shows the results of compound (I) being further evaluated in a proof-of-concept study in a mouse model for the treatment of urinary tract infections caused by Gram-negative bacteria of the order Enterobacteriaceae. Same as above. Same as above.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a solution to a previously unmet clinical need for the treatment of infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriaceae, particularly carbapenem-resistant Enterobacteriaceae (CRE) and extended-spectrum β-lactamase (ESBL) Enterobacteriaceae bacteria. The present invention can also be utilized in the treatment of infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the genus Haemophilus.

It has surprisingly and advantageously been found that compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof enables the treatment of infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, such as Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, which are resistant to known β-lactam antibiotics and are a major cause of death.

Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof may be particularly advantageous in treating multisite infections, i.e., infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, occurring at different infection sites (intracellular sites in tissues and/or organs) in a subject (as demonstrated by the data provided in the Examples section of this application). When antibacterial treatment of a disease or infection in a subject in need of treatment has failed, or when the subject is allergic or otherwise contraindicated to a drug used or contemplated for use in antibacterial treatment, compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof may be further advantageously utilized in treating infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus.

Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof appears to have rapid bactericidal activity and is believed to be highly active against all currently tested clinical resistance mechanisms, including all Ambler β-lactamase classes (including metallo-β-lactams). Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof appears to be resistant to inactivation by the full range of carbapenem-metabolizing enzymes and has demonstrated activity against all currently tested CREs, regardless of carbapenemase or other resistance characteristics. In contrast to known BL/BLI combination treatments, compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof has shown a low propensity for resistance development when tested in vitro.

Furthermore, compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof does not exhibit cross-resistance with currently tested classes of antibiotics, and no contraindications have been observed. Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof has also demonstrated safety both in vitro and in vivo in pharmacological studies.

Therefore, compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof can be used to treat bacterial infections or diseases caused by or exacerbated by bacteria resistant to known antibiotics, such as Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, particularly bacteria resistant to known antibiotics, such as carbapenem-resistant Enterobacteriale (CRE) and extended-spectrum β-lactamase (ESBL) Enterobacteriale bacteria. Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof has bactericidal activity against bacteria resistant to known antibiotics, such as Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, particularly bacteria resistant to known antibiotics, such as carbapenem-resistant Enterobacteriale (CRE) and extended-spectrum β-lactamase (ESBL) Enterobacteriale bacteria.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can target one or more Gram-negative bacteria of the order Enterobacteriale. Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can target one or more Gram-negative bacteria of the family and genera of the order Enterobacteriale of Gram-negative bacteria. The order Enterobacteriale includes the families Enterobacteriaceae, Budviciaceae, Erwiniaceae, Hafniaceae, Morganellaceae, Pectobacteriaceae, and Yersiniaceae, and all genera thereof. Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can target one or more of the following genera of Gram-negative bacteria in the order Enterobacteriale: Arsenophonus, Atlantibacter, Biostraticola, Brenneria, Buchnera, Budvicia, Buttiauxella, Cedecea, Chania, Citrobacter, Cosenzaea, Cronobacter, Dickeya, Edwardsiella, and the like. Edwardsiella, Enterobacillus, Enterobacter, Erwinia, Escherichia, Ewingella, Franconibacter, Gibbsiella, Hafnia, Izhakiella, Kosakonia, Klebsiella, Kluyvera, Leclercia, Lelliottia, Leminorella, Levinea, Lonsdalea ea), Mangrovibacter, Moellerella, Morganella, Obesumbacterium, Pantoea, Pectobacterium, Phaseolubacter, Photorhabdus, Plesiomonas, Pluralibacter, Pragia, Proteus, Providencia, Pseudocitrobacter, Rahnella, Rhodotorula, Rhodotorula aoultella, Rosenbergiella, Rouxiella, Saccharobacter, Salmonella, Samsonia, Serratia, Shigella, Shimwellia, Siccibacter, Sodalis, Tatumella, Thorsellia, Trabulsiella, Wigglesworthia, Xenorhabdus, Yersinia, and Yokenella.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can target one or more Gram-negative bacteria of the genus Haemophilus. Gram-negative bacteria of the genus Haemophilus belong to the family Pasteurellaceae, order Pasteurellales.

Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, targets one or more Gram-negative bacteria of the order Enterobacteriaceae. Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is used to treat infection with, or a disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, will typically have the same or similar activity against all Gram-negative bacteria of the order Enterobacteriale. This is a result of the sufficiently high sequence homology among Gram-negative bacteria of the order Enterobacteriale. Therefore, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, will interact similarly with all Gram-negative bacteria of the order Enterobacteriale. This is particularly true for selected Enterobacteriale bacterial genera, detailed below. Preferably, Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, targets one or more Gram-negative bacteria from the Enterobacteriaceae order bacterial genera Cedecea, Citrobacter, Erwinia, Escherichia, Enterobacter, Klebsiella, Kluyvera, Plesiomonas, Proteus, Providencia, Raoultella, Salmonella, Serratia, Shigella, and Yersinia. More preferably, Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, targets one or more Gram-negative bacteria from the Enterobacteriale order bacterial genera Erwinia, Escherichia, Enterobacter, Klebsiella, Proteus, Salmonella, Serratia, Shigella, and Yersinia. The genus Escherichia includes Escherichia coli, such as extraintestinal pathogenic Escherichia coli (ExPEC) strains and carbapenem-resistant Escherichia coli strains, e.g., Escherichia coli of sequence type ST131 and Escherichia coli ATCC BAA-2469 (NDM-1 strain: American Type Culture Collection). The genus Enterobacter includes Enterobacter spp. The genus Klebsiella includes Klebsiella pneumoniae, including carbapenem-resistant Klebsiella pneumoniae strains, such as Klebsiella pneumoniae of sequence type ST25 and Klebsiella pneumoniae ATCC 43816 (American Type Culture Collection). Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, targets one or more Gram-negative bacteria from the Enterobacteriale bacterial genera Escherichia, Enterobacter, and Klebsiella, more preferably Escherichia and Klebsiella. Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, targets Enterobacter spp., Escherichia coli, and Klebsiella pneumoniae, more preferably Escherichia coli and Klebsiella pneumoniae.

The one or more Gram-negative bacteria targeted by compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, are typically multidrug-resistant, including carbapenem-resistant or β-lactam-resistant, and exhibit resistance to these known antibiotics and related antibacterial treatments. Examples of such bacteria include carbapenem-resistant Escherichia coli ATCC BAA-2469, ExPEC Escherichia coli ST131, Klebsiella pneumoniae ST258, and Klebsiella pneumoniae ATCC 42816.

The National Collection of Type Cultures (NCTC) reference strain for ExPEC Escherichia coli ST131 is NCTC13441. Further details regarding ExPEC Escherichia coli ST131 are provided in Pitout et al., ‘Escherichia coli ST131: a multidrug-resistant clone primed for global domination’, F1000Research 2017, 6(F1000 Faculty Rev):195; Ciesielczuk et al., ‘Trends in ExPEC serogroups in the UK and their significance’, Eur J Clin Microbial Infect Dis (2016) 35:1661-1666; Day et al., ‘Extended-spectrum β-lactamase-producing Escherichia coli in human-derived and food chain-derived samples from England, Wales, and Scotland: an epidemiological surveillance and typing study’, Lancet Infect Dis 2019, vol. 19; and Day et al., ‘Population structure of Escherichia coli causing bacteraemia in the UK and Ireland between 2001 and 2010’, J Antimicrob Chemother 2016, 71, 2139-2142.

The National Collection of Type Cultures (NCTC) reference strain for Klebsiella pneumoniae ST258 is NCTC 13438. Further details on Klebsiella pneumoniae ST258 are provided in: Chen et al., "Carbapenemase-producing Klebsiella pneumonia: molecular and genetic decoding," Trends Microbiol., December 2014, 22(12), 686-696.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat infections caused by Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus in the form of biofilms.

Diseases or infections caused by or exacerbated by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus may include intoxication by one or more bacterial toxins, including, for example, endotoxins, exotoxins, and/or toxic enzymes. Accordingly, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, finds application in the treatment of Enterobacteriale and/or Haemophilus intoxication. In such cases, treatment of intoxication by bacterial endotoxins, exotoxins, and/or toxic enzymes, e.g., endotoxins, exotoxins, and/or toxic enzymes produced by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, is preferred.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat the human body, i.e., the subject to be treated is a human, as described in various aspects of this specification.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can also be used to treat the animal body, i.e., the subject being treated is an animal, particularly for treating commercial animals such as livestock. Alternatively, Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat companion animals such as cats and dogs. It will be understood that treatment of the animal body is carried out in a similar manner for all subjects, i.e., both humans and animals.

Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is used to treat the human body, i.e., the subject to be treated is a human.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus. Specifically, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat bacteremia or bloodstream infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, pyelonephritis (kidney infection) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and intraperitoneal infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus. In particular, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat bacteremia or bloodstream infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, pyelonephritis (kidney infection) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and intraperitoneal infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus when antibacterial treatment of the infection has failed. It is further noted that compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or protected form thereof, can be used to treat bacteremia or bloodstream infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, pyelonephritis (kidney infection) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and intraperitoneal infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, when the subject in need of treatment is allergic to or otherwise contraindicated to the agent used in the antibacterial treatment.

Bacteremia or bloodstream infections caused by gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus can lead to conditions such as sepsis (also known as septicaemia).

Respiratory infections caused by Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus include infections of the airways or lungs, including pneumonia. In the context of the present invention, pneumonia typically refers to healthcare pneumonia, including hospital-acquired pneumonia and ventilator-associated pneumonia, or pneumonia that results in the subject being hospitalized.

Urinary tract infections (UTIs) caused by gram-negative bacteria of the order Enterobacteriaceae and/or the genus Haemophilus include uncomplicated and complicated UTIs affecting the bladder (cystitis), urethra (urethritis), or kidneys (renal infection).

Intra-abdominal infections (IAI) caused by gram-negative Enterobacteriaceae and/or Haemophilus genus bacteria can cause conditions such as peritonitis, diverticulitis, cholecystitis, cholangitis, and pancreatitis.

Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or protected form thereof, can be used to treat bacteremia or bloodstream infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and more preferably, respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus.

Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof may be effective in treating multisite infections, i.e., infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, occurring at different infection sites (intracellular sites in tissues and/or organs) in a subject (as demonstrated by the data provided in the Examples section of this application). This may be the case, for example, in both the bloodstream to treat bacteremia or bloodstream infections caused by or exacerbated by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and in the respiratory organs to treat respiratory infections caused by or exacerbated by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus. It will be understood that infections at multiple sites are typically caused by or exacerbated by the same species of Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus. Infections with Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus may occur simultaneously or subsequently in different tissues and/or organs of a subject. Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used for multi-site treatment of infections with Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, or diseases caused or exacerbated by them.

As indicated above, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, may be utilized, particularly after unsuccessful empirical antibacterial treatment with known antibiotics that are considered standard of care for treating an alleged infection. Thus, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, may be utilized after antibiotic-resistant Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus have been determined to be the cause of a subject's infection or disease.

After determining the presence of antibiotic-resistant Enterobacteriale gram-negative bacteria and/or Haemophilus gram-negative bacteria, e.g., carbapenem-resistant Enterobacteriale (CRE) or extended-spectrum β-lactamase (ESBL) Enterobacteriale bacteria that are resistant to known β-lactam antibiotics, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat infections in a subject caused by, or caused by, or exacerbated by, these resistant Enterobacteriale and/or Haemophilus strains.

Methods for determining the presence of antibiotic-resistant Enterobacteriale gram-negative bacteria and/or Haemophilus gram-negative bacteria, such as carbapenem-resistant Enterobacteriale (CRE) or extended-spectrum β-lactamase (ESBL) Enterobacteriale bacteria, will be well known to those skilled in the art. Suitable methods include those disclosed in Al-Zahrani, "Routine detection of carbapenem-resistant gram-negative bacilli in clinical laboratories," Saudi Medical Journal, 2018 September, pp. 861-872.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used in any clinical practice or treatment. For example, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used in a hospital setting, e.g., for hospitalized subjects with severe illness. Alternatively or additionally, compound (I) can be used in outpatient treatment, such as outpatient parenteral antimicrobial therapy (OPAT), or by subjects in a home setting. As noted above, treatment with compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be administered after unsuccessful antimicrobial treatment. However, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can also be used as a first-line antimicrobial treatment, e.g., in settings with high infection rates, e.g., during a community or local epidemic.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be used to treat hospital-acquired infections (HAIs) caused by gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus, e.g., introduced via a central line or catheter.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can be formulated as a pharmaceutical composition together with a pharmaceutically acceptable carrier or excipient. Suitable pharmaceutically acceptable carriers and excipients depend on the mode of administration of the pharmaceutical composition and are described in more detail below. Typically, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is administered in a pharmaceutical composition further comprising a pharmaceutically acceptable carrier or excipient.

The pharmaceutical compositions claimed herein may further comprise pharmaceutically acceptable ingredients selected from, but not limited to, stabilizers, antioxidants, colorants, diluents, and combinations thereof. The ingredients of the pharmaceutical composition are selected so as to minimize side effects and not impair the performance of Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, to an extent that treatment becomes ineffective.

The pharmaceutical compositions according to the present invention may be administered to a subject in need thereof by any suitable route, including, but not limited to, enteral administration, for example oral, rectal, gastric or duodenal administration; parenteral administration (such as intravenous by injection or infusion); vaginal, buccal or sublingual administration; topical administration or inhalation.

Parenteral administration includes subcutaneous, intravenous, intradermal, intramuscular, and intraperitoneal administration, as well as injection techniques such as sterile injectable aqueous emulsions and oily suspensions. Such suspensions can be formulated according to known techniques using suitable dispersing or wetting agents and suspending agents. Sterile injectable preparations can also be sterile injectable solutions or suspensions in a non-toxic parenterally acceptable diluent or solvent, such as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be used are water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally used as solvents or suspending media. For this purpose, any mild, fixed oil can be used, including synthetic mono- or diglycerides. In addition, omega-3 polyunsaturated fatty acids can also find use in the preparation of injectables.

Preferably, intravenous administration to a human subject can be given in the form of either a bolus (injected all at once) (IV bolus) or an intravenous infusion (IV infusion), e.g., slowly injected into the plasma through a vein of the subject at a constant or zero-order rate. Preferably, intravenous administration is administered in the form of an intravenous infusion (IV infusion).

Such intravenous infusions, preferably into human subjects, can be provided as isotonic solutions. Such solutions generally have an osmolality of 250-375 mOsm/L. Preferred examples of isotonic solutions include normal saline (preferably about 0.9% sodium chloride), phosphate-buffered saline, lactated Ringer's solution, about 5% dextrose in water (D5W), and Ringer's solution. For intravenous infusion, isotonic solutions preferably have a pH of 5-8, e.g., 6-8 or 7.1-7.5.

For subcutaneous, intravenous, intramuscular, inhalation, or intraperitoneal administration, Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, may be provided as an injectable dose in a pharmaceutically acceptable diluent (which may be a sterile liquid or mixture of liquids) together with a pharmaceutically acceptable excipient or carrier.

For intramuscular, intraperitoneal, subcutaneous, inhalation, and intravenous use, Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, will generally be provided in a sterile aqueous solution or suspension buffered to an appropriate pH and isotonicity.

Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, or a pharmaceutical composition formulated therefrom, is administered parenterally or by inhalation, more preferably intravenously, more preferably intravenously in the form of an intravenous infusion (IV infusion). Most preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is administered intravenously to a human subject, particularly in the form of an intravenous infusion (IV infusion).

Pharmaceutically acceptable excipients and carriers include all of the foregoing and more. The above considerations regarding effective formulation and administration procedures are well known in the art and are described in standard textbooks. See, for example, Remington: The Science and Practice of Pharmacy, 20th Edition (Lippincott, Williams and Wilkins), 2000; Lieberman et al., ed., Pharmaceutical Dosage Forms, Marcel Decker, New York, N.Y. (1980); and Kibbe et al., ed., Handbook of Pharmaceutical Excipients (3rd Edition), American Pharmaceutical Association, Washington (1999).

In addition to hydroxypropyl beta-cyclodextrin and phosphate buffer, suitable pharmaceutically acceptable carriers or excipients for use in the pharmaceutical compositions of the present invention include isotonic solutions, such as saline (preferably about 0.9% sodium chloride), phosphate-buffered saline, lactated Ringer's solution, about 5% dextrose in water (D5W), and Ringer's solution. The isotonic solution preferably has a pH of 5 to 8, for example, 6 to 8 or 7.1 to 7.5. The pH of the phosphate buffer may be 5 to 7, preferably 6.

For intravenous infusion into a human subject, the pharmaceutically acceptable carrier or excipient may be selected from saline (preferably about 0.9% sodium chloride), phosphate buffered saline, lactated Ringer's solution, about 5% dextrose in water (D5W), Ringer's solution, and an acid buffer. The pH of the phosphate buffer may be 5 to 7, preferably 6. Preferably, for intravenous infusion into a human subject, the pharmaceutically acceptable carrier or excipient is a phosphate buffer, preferably at pH 6.

For compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, the dosage of compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof will, of course, vary depending on the mode of administration, the desired treatment, and the infection or disease being treated.

The size of a dose of Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, for therapeutic purposes will, of course, vary depending on the nature and severity of the condition, the age and sex of the subject, and the mode of administration, in accordance with well-known principles of medicine.

Dosage levels, dosing frequency, and duration of treatment of Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, are expected to vary depending on the formulation, mode of administration, and the patient's clinical indication, age, and comorbid medical conditions.

When the method of administration is intravenous infusion to a human subject, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can typically be administered in a pharmaceutical composition according to the present invention at a dose of 50 to 6000 mg per day. Preferably, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is administered at a dose of 50 to 4000 mg per day, or 50 to 3000 mg per day, for example, 50 to 2000 mg per day, or 100 to 2000 mg per day, for example, 200 to 2000 mg per day, or 200 to 1750 mg per day, or 200 to 1500 mg per day, or 250 to 1000 mg per day. When compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is administered more than once daily, such as twice or three times daily, as discussed below, the dose is divided according to the number of times per day it is administered.

When the method of administration is intravenous infusion to a human subject, Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, may be administered at the above-mentioned doses once (QD), twice (BID), or three times (TID). Twice-daily (BID) administration by intravenous infusion to a human subject includes twice-daily administration spaced 1 to 12 hours apart, e.g., 1 to 8 hours, or 2 to 7 hours, or 2 to 6 hours, or 3 to 5 hours apart, e.g., 1 to 4 hours apart. Three-times-daily (TID) administration by intravenous infusion to a human subject includes three-times-daily administration spaced 2 to 7 hours apart, or 2 to 6 hours, or 3 to 5 hours apart, e.g., 1 to 4 hours apart. The number of hours is calculated from the time the first administration is initiated, which is the period from the start of the first administration to the start of the second administration. It will be further understood that when administered twice or three times daily, the same dose or different doses can be administered each time. Each dose of intravenous infusion may be administered over a period of 30 minutes to 6 hours, for example, 30 minutes to 4 hours, or 30 minutes to 3 hours, or 30 minutes to 2 hours, or 30 minutes to 1 hour, or about 1 hour.

Preferably, compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is administered by intravenous infusion to a human subject at the above-mentioned daily dose once daily (QD), twice daily (BID), at intervals of 1 to 12 hours, for example, at intervals of 1 to 8 hours, or at intervals of 2 to 6 hours, or at intervals of 2 to 5 hours, or at intervals of 3 to 5 hours, or at intervals of 1 to 4 hours, or three times daily (TID), at intervals of 2 to 7 hours, for example, at intervals of 2 to 6 hours, or at intervals of 3 to 5 hours, for example, at intervals of 1 to 4 hours. More preferably, compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is administered by intravenous infusion to a human subject at the above-mentioned daily dose twice daily, at intervals of 1 to 12 hours, for example, at intervals of 1 to 8 hours, or at intervals of 2 to 6 hours, or at intervals of 2 to 5 hours, or at intervals of 3 to 5 hours, or at intervals of 1 to 4 hours.

When the method of administration is intravenous infusion to a human subject, compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or protected form thereof, is preferably used to treat respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and/or urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, at the above-mentioned daily doses and administrations.

When the method of administration is intravenous infusion into a human subject, at the above doses and administrations per day, the course of treatment may last for 1 to 10 days, for example, 1 to 7 days, or 1 to 5 days. By "course of treatment" is meant the period during which treatment is administered on consecutive days.

Therefore, the pharmaceutical composition according to the present invention comprising compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is preferably administered at a dose of 50 to 6000 mg per day, or 50 to 4000 mg per day, or 50 to 3000 mg per day, for example, 50 to 2000 mg per day, or 100 to 2000 mg per day, for example, 200 to 2000 mg per day, or 200 to 1750 mg per day, or 200 to 1500 mg per day, or 250 to 1000 mg per day, It may be administered to a human subject by intravenous infusion once daily (QID), twice daily (BID), or three times daily (TID), more preferably once daily (QID) or twice daily (BID), at intervals of 1 to 12 hours, for example, at intervals of 1 to 8 hours, or at intervals of 2 to 6 hours, or at intervals of 2 to 5 hours, or at intervals of 3 to 5 hours, or at intervals of 1 to 4 hours, or three times daily (TID), at intervals of 2 to 7 hours, for example, at intervals of 2 to 6 hours, or at intervals of 3 to 5 hours, for example, at intervals of 1 to 4 hours, more preferably twice daily, at intervals of 1 to 12 hours, for example, at intervals of 1 to 8 hours, or at intervals of 2 to 6 hours, or at intervals of 2 to 5 hours, or at intervals of 3 to 5 hours, or at intervals of 1 to 4 hours.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, may be in any form. It may be synthesized, purified, or isolated from natural sources using techniques described in the art.

Compound (I) can be obtained, stored, and/or administered in the form of a pharmaceutically acceptable salt. Exemplary pharmaceutically acceptable salts are prepared from formic acid, acetic acid, propionic acid, succinic acid, glycolic acid, gluconic acid, lactic acid, malic acid, tartaric acid, citric acid, ascorbic acid, glucuronic acid, maleic acid, fumaric acid, pyruvic acid, aspartic acid, glutamic acid, benzoic acid, anthranilic acid, mesylic acid, stearic acid, salicylic acid, p-hydroxybenzoic acid, phenylacetic acid, mandelic acid, embonic (pamoic) acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, pantothenic acid, toluenesulfonic acid, 2-hydroxyethanesulfonic acid, sulfanilic acid, cyclohexylaminosulfonic acid, algenic acid, β-hydroxybutyric acid, galactaric acid, and galacturonic acid.

Suitable pharmaceutically acceptable base addition salts include metal ion salts and organic ion salts. Metal ion salts include, but are not limited to, appropriate alkali metal (Group Ia) salts, alkaline earth metal (Group IIa) salts, and other physiologically acceptable metal ions. Such salts can be made from aluminum, calcium, lithium, magnesium, potassium, sodium, and zinc ions. Organic salts can be made from tertiary amines and quaternary ammonium salts, such as trimethylamine, diethylamine, N,N'-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine), and procaine. All of the above salts can be prepared by those skilled in the art from the corresponding compounds by conventional means. Conventional procedures for the selection and preparation of suitable pharmaceutical formulations are described, for example, in "Pharmaceuticals - The Science of Dosage Form Designs," M. E. Aulton, Churchill Livingstone, 1988.

Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, can also be used for the in vitro inhibition of the growth of Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, particularly carbapenem-resistant Enterobacteriale (CRE) and extended-spectrum β-lactamase (ESBL) Enterobacteriale bacteria. Accordingly, the present invention further encompasses an in vitro method for inhibiting the growth of Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, particularly carbapenem-resistant Enterobacteriale (CRE) and extended-spectrum β-lactamase (ESBL) Enterobacteriale bacteria, using compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof can be synthesized by any suitable method.

Suitable methods for synthesizing compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof include, but are not limited to, methods corresponding to synthetic route 1 of WO2019/086890.

Compound (I) can be synthesized according to the following method. This method represents a preferred method for synthesizing compound (I), and the method includes a preferred linking step detailed below. However, it will be understood that, in the context of the present invention, these preferred steps are separable, and one or more of the steps can be replaced with any other suitable step identified by one of skill in the art. If step X has options A and B, e.g., step 6A or step 6B, then either step XA or XB can be utilized as step X, i.e., either step 6A or 6B can be utilized as step 6.

Step 1

A 20 L four-neck round-bottom flask equipped with a mechanical stirrer was charged with 1-(3,4-dihydro-2H-1,4-benzoxazin-6-yl)ethan-1-one (1) (300 g, 1.69 mol) at room temperature. A solution of HBr in glacial acetic acid (33% w/w, 2.10 L, 7 V) was added dropwise at 10°C, ideally maintaining the internal temperature below about 12°C. To the resulting reaction mixture at 10°C (internal temperature) was added a solution of bromine (86.7 mL, 1.69 mol) in glacial acetic acid (450 mL, 1.5 V relative to starting material) slowly (over about 90 min) such that the internal temperature remained below 10°C. The reaction was monitored by LCMS. After complete addition of the solution of bromine in glacial acetic acid, crude LCMS confirmed approximately 10% unconsumed starting material (1-(3,4-dihydro-2H-1,4-benzoxazin-6-yl)ethan-1-one (1)) and approximately 30% conversion to the desired monobrominated product (2), along with approximately 24% dibrominated by-product. The cooling bath was removed, and the reaction mixture was gradually warmed to 25° C. (internal temperature) over approximately 1 hour. The resulting reaction mixture was further stirred at 40° C. (internal temperature) for 1.5 hours [a visible precipitate was observed, and crude LCMS confirmed unconsumed starting material (1) (approximately 4%), along with the desired monobrominated product (2) (55%) and dibrominated by-product (approximately 18%)]. The reaction mixture was cooled to 10° C., diluted with MTBE (4.9 L, 16 V), and stirred for 1 hour. The resulting precipitate was filtered, washed with MTBE (600 mL), and dried under reduced pressure to give 340 g (a mixture of mono- and dibrominated products) as an off-white solid. LCMS of the resulting solid indicated a mixture of 2-bromo-1-(3,4-dihydro-2H-1,4-benzoxazin-6-yl)ethan-1-one. HBr (2) (approximately 87%, monobrominated), 2,2-dibromo-1-(3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)ethan-1-one (approximately 5%, dibrominated by-product), and unconsumed 1-(3,4-dihydro-2H-1,4-benzoxazin-6-yl)ethan-1-one (1) (approximately 1%). This mixture was used in the next step without further purification. The calculated isolated yield based on the monobrominated product (2) observed by LCMS was found to be 52%. MS (ESI+) m/z 255.96 [M+H] ⁺ for CHNOS; ^1H NMR (400 MHz, DMSO-d6): δ 7.19-7.28 (m, 2H), 6.77 (d, J = 8.4 Hz, 1H), 4.74 (s, 2H), 4.31 (t, J = 4.4 Hz, 2H), and 3.32 (t, J = 4.4 Hz, 2H).

Step 2

A 10 L four-neck round-bottom flask equipped with a mechanical stirrer was charged with THF (3.50 L, 7 V) and 2-bromo-1-(3,4-dihydro-2H-1,4-benzoxazin-6-yl)ethan-1-one.HBr(2) (500 g, 1.48 mol) at 20° C. To the resulting reaction mixture was added acetyl chloride (476 mL, 6.68 mol) dropwise while maintaining the temperature at 20° C. A 2° C. increase in reaction temperature was observed during the addition of acetyl chloride to the reaction mixture. The reaction mixture was further stirred at 30° C. for 16 h. The reaction was monitored by LCMS. Crude LCMS confirmed the formation of a 1:1 ratio mixture of 1-(4-acetyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-bromoethan-1-one and 1-(4-acetyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-chloroethan-1-one. The reaction mixture was cooled to approximately 10°C, basified with 10% _{aqueous K2CO3} solution (5.0 L) to a pH of approximately 8.0, and extracted with ethyl acetate (3 x 5 L). The combined organic layers were washed with brine (5.0 L) and concentrated under reduced pressure to give the crude product as a brown liquid. The brown liquid was cooled to 10°C, diluted with hexanes (4.0 L), and stirred at 10°C for 1 hour. The resulting precipitate was filtered, washed with hexane (1.0 L), and dried under vacuum to give a mixture of 1-(4-acetyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-bromoethan-1-one (3) and 1-(4-acetyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-chloroethan-1-one (4) as a light brown solid (387 g, 92% pure by LCMS), which was used in the next step without further purification. MS (ESI+) m/z for CHNOS: 297.99 [M+H] ⁺ and 254.05 [M+H] ⁺ .

Step 3

A 5.0 L four-neck round-bottom flask equipped with a mechanical stirrer was charged with a mixture of EtOH (2.0 L, 3V), 1-(4-acetyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-bromoethan-1-one (3) and 1-(4-acetyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-chloroethan-1-one (3A) (685 g, 2.30 mol, 92% purity by LCMS), followed by the addition of pyrimidin-2-amine (4) (546 g, 5.74 mol) at 20° C. The reaction mixture was further stirred and refluxed for 3 h. The reaction was monitored by LCMS. The reaction mixture was cooled to room temperature (approximately 20° C.) and the resulting precipitated solid was filtered, washed with EtOH (2×250 mL), and dried under vacuum to give 1-(6-(imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (5) as an off-white solid (418 g). MS (ESI+) m/z 295.06 [M+H] ⁺ for CHNOS. 1H NMR (400 MHz, DMSO-d6 + d-TFA): δ 9.27 (d, J = 6.40 Hz, 1H), 8.97-9.02 (m, 1H), 8.65 (s, 1H), 8.44 (bs, 1H), 7.63-7.69 (m, 2H), 7.10 (d, J = 8.40 Hz, 1H), 4.33-4.36 (m, 2H), 3.89-3.93 (m, 2H), 2.32 (s, 3H). The regioisomeric structure was confirmed by nOe.

Step 4

A 10 L four-neck round-bottom flask equipped with a mechanical stirrer was charged with N,N-dimethylacetamide (2.0 L), 1-(6-(imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (5) (250 g, 849 mmol), 2,2-dimethylpropanoic acid (34.7 g, 340 mmol), potassium carbonate (587 g, 4.25 mol), and 4-bromo-3-methylpyridine (6) (264 g, 1.44 mol) at 20 °C under a _N atmosphere. The resulting reaction mixture was purged with _N2 (gas) for 30 minutes, followed by the addition _of Pd(OAc) ₂ (19.1 g, 84.9 mmol) and _PCy3.HBF4 (31.2 g, 84.9 mmol) under a _N2 atmosphere. The reaction mixture was again purged with _N2 (gas) for an additional 15 minutes. The resulting reaction mixture was further stirred at 125°C for 7 hours. The reaction was monitored by LCMS. Crude LCMS confirmed the formation of a regioisomeric mixture of the desired product with a regioisomeric ratio of 98:2. The reaction mixture was filtered through a celite bed (height 1.3 cm, diameter 25 cm). The celite bed was washed with 10% MeOH in DCM (15 L). The filtrate was evaporated under reduced pressure to give the crude residue as a brown liquid. The brown liquid was stirred in heptane (3 x 6.0 L) for 10 hours to remove excess DMA. The heptane/DMA mixture was decanted (a trace of the desired product was observed in the decanted fractions) to give a waxy solid. The waxy solid was stirred in MTBE (3.0 L) for an additional 15 minutes. The resulting precipitate was filtered and washed with MTBE (2.0 L) to give the desired product as a brown solid. The brown solid was passed through a small silica plug and eluted with 10% MeOH in DCM (approximately 35 L). The resulting solvent fractions were concentrated to 1/10 of their original volume. The concentrated fractions were diluted with MTBE (200 mL) and stirred for 30 minutes. The resulting precipitate was filtered, washed with MTBE (1.0 L), and dried under vacuum to give a regioisomeric mixture of 1-(6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (7) and 1-(6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (7A) as a light brown solid. Yield: 66% (97% by LCMS, regioisomeric ratio 98:2). MS of CHNOS (ESI+) m/z 386.18 [M+1] ⁺ . 1H NMR (400 MHz, DMSO-d6 + d-TFA): δ 9.14 (s, 1H), 9.01-9.04 (m, 2H), 8.86 (d, J = 6.7 Hz, 1H), 8.23 (d, J = 5.8 Hz, 1H), 8.01 (bs, 1H), 7.55-7.58 (m, 1H), 7.41(d, J = 8.3 Hz, 1H), 7.05 (d, J = 8.6 Hz, 1H), 4.09-4.33 (m, 2H), 3.71-3.92 (m, 2H), 2.17 (s, 3H), 2.11 (bs, 3H).

Step 5A

To a solution of a regioisomeric mixture (97:3) of 1-(6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (7) and 1-(6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (7A) (24.0 g, 62.3 mmol) in methanol (150 mL) was added 6.0 N aqueous HCl (62 mL) at room temperature. The reaction mixture was stirred at 90° C. for 16 hours. The reaction mixture was cooled to room temperature and concentrated to one-quarter of its original volume. The concentrated reaction mixture was basified to pH 8-9 with saturated aqueous NaHCO3 and extracted with 10% MeOH in DCM (3 x 250 mL). The organic layer was washed with brine (300 mL), dried over ( _Na2SO4 ), filtered, and concentrated under reduced pressure to 1/10 of its original volume. The concentrated mixture was diluted with heptane (100 _mL ) and stirred for 30 minutes. The resulting precipitate was filtered, washed with heptane (100 mL), and dried under reduced pressure to give a mixture of 6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8) and 6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8A) (20.0 g) as a yellow solid. Yield: 71% (mixture of two regioisomers in a 2:1 regioisomeric ratio, 89% by LCMS). LCMS showed two peaks with 56% and 33% of the desired mass, respectively. (ESI+) m/z 344.20 [M+H] ⁺ for CHNOS.

Or step 5B

A suspension of a regioisomeric mixture (98:2) of 1-(6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (7) and 1-(6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (7A) (10.0 g, 25.9 mmol) in 2.0 M aqueous NaOH solution (52 mL, 104 mmol) was heated at 100° C. for 24 hours. The reaction was monitored by LCMS. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered. The filter cake was washed with water (approximately 500 mL) and dried to give a mixture of 6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8) and 6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8A) as a light brown solid. Yield: 8.1 g, 90% (mixture of two regioisomers in a regioisomeric ratio of 98:2, 98.7% by LCMS). MS of CHNOS (ESI+) m/z 344.20 [M+H] ⁺ ; ¹ H NMR (400 MHz, DMSO-d ₆ ): δ 8.69 (s, 1H), 8.54-8.62 (m, 2H), 8.25 (d, J = 6.8 Hz, 1H), 7.46 (d, J = 4.8 Hz, 1H), 6.96-7.03 (m, 2H), 6.46-6.55 (m, 2H), 5.87 (s, 1H), 4.11 (t, J = 4.0 Hz, 2H), 3.25 (bs, 2H), 1.94 (s, 3H).

Step 6A (HMPA-mediated amino acid coupling)

To a suspension of 2-amino-2-methylpropanoic acid (9) (12 g, 116 mmol) in HMPA (84 mL, 7V) was added slowly a solution of thionyl chloride (9.29 g, 128 mmol) in ACN (8.4 mL) at 3° C. (external temperature was 0° C.) 10 min after complete addition of the solution of thionyl chloride in ACN, the suspension became clear. The resulting reaction mixture was stirred at 0° C. for 20 minutes, followed by the addition of a regioisomeric mixture of 6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8) and 6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8A) (8 g, 23.3 mmol) portionwise at 0° C. The reaction mixture was allowed to warm to room temperature and stirred for 16 hours. The reaction was monitored by LCMS. After completion of the reaction, the reaction mixture was diluted with EtOAc (300 mL). The resulting precipitate was filtered and washed with EtOAc (250 mL). The solid was dissolved in water (50 mL), neutralized to pH 8 with saturated sodium bicarbonate solution, extracted with 10% MeOH in DCM (4 x 100 mL), and concentrated under reduced pressure to 1/10 of the original reaction mixture volume. The crude mixture was diluted with MTBE (50 mL) and stirred for 15 min. The resulting precipitate was filtered, washed with MTBE (25 mL), and dried under vacuum to give a regioisomeric mixture of 2-amino-2-methyl-1-(6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)propan-1-one (10) and 2-amino-2-methyl-1-(6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)propan-1-one (10A) as a brown solid. Yield: 66% (97% by LCMS, regioisomeric ratio 98:2). MS of CHNOS (ESI+) m/z 429.16 [M+1] ⁺ ; ¹ H NMR (400 MHz, DMSO-d ₆ ): δ 8.69 (s, 1H), 8.54-8.62 (m, 2H), 8.29 (d, J = 5.2 Hz, 1H), 8.12 (d, J = 1.6 Hz, 1H), 7.46 (d, J = 4.8 Hz, 1H), 6.98-7.05 (m, 2H), 6.77 (d, J = 8.4 Hz, 1H), 4.45- 4.67 (m, 2H), 4.30 (bs, 2H), 2.12 (bs, 2H), 1.97 (s, 3H), 1.34 (s, 6H).

Alternatively, Step 6B (DMPU-mediated amino acid coupling)

To a solution of 2-amino-2-methylpropanoic acid (9) (2.0 g, 19.4 mmol) in DMPU (14 mL) was slowly added a solution of thionyl chloride (1.55 mL, 21.3 mmol) in ACN (1.4 mL) at 4 °C (external temperature 0 °C). The resulting reaction mixture was stirred at 0 °C for 20 minutes, followed by the addition of a 98:1 regioisomeric mixture of 6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8) and 6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (8A) in portions at 0 °C. The reaction mixture was warmed to room temperature and stirred for 16 hours. After completion of the reaction (LCMS monitoring), the reaction mixture was diluted with EtOAc (50 mL). The resulting precipitate was filtered and washed with EtOAc (50 mL). The solid was dissolved in water (100 mL), basified with saturated sodium bicarbonate solution to pH 8.0, extracted with 10% MeOH in DCM (3 x 100 mL), dried _{( Na2SO4} ), and concentrated under reduced pressure to give a crude residue. The crude residue was further stirred in MTBE (20 mL), filtered, washed with MTBE (20 mL), and dried under vacuum to afford a regioisomeric mixture of 2-amino-2-methyl-1-(6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)propan-1-one (10) and 2-amino-2-methyl-1-(6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)propan-1-one (10A) as a brown solid, which was used further in the next step without further purification. MS of CHNOS (ESI+) m/z 429.16 [M+1] ⁺ ; ¹ H NMR (400 MHz, DMSO-d ₆ ): δ 8.69 (s, 1H), 8.54-8.62 (m, 2H), 8.29 (d, J = 5.2 Hz, 1H), 8.12 (d, J = 1.6 Hz, 1H), 7.46 (d, J = 4.8 Hz, 1H), 6.98-7.05 (m, 2H), 6.77 (d, J = 8.4 Hz, 1H), 4.45- 4.67 (m, 2H), 4.30 (bs, 2H), 2.12 (bs, 2H), 1.97 (s, 3H), 1.34 (s, 6H).

Step 7

To a suspension of a 98:2 regioisomeric mixture of 2-amino-2-methyl-1-(6-(3-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-2-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)propan-1-one (10) and 2-amino-2-methyl-1-(6-(2-(3-methylpyridin-4-yl)imidazo[1,2-a]pyrimidin-3-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)propan-1-one (10A) (8.6 g, 93% by LCMS, 20.1 mmol) in isopropyl alcohol (60 mL) was added hydroxylamine hydrochloride (3.49 g, 50.2 mmol) at room temperature. The resulting suspension was stirred at 70° C. for 22 hours. The reaction was monitored by LCMS. Crude LCMS showed the formation of the desired product along with traces of deamidated by-products (1-2% by crude LCMS) and unreacted starting material (2-3% by LCMS). The resulting suspension was cooled to room temperature, diluted with acetone (100 mL), and stirred for 1 hour. The reaction mixture was concentrated to 20% of the original volume, and the precipitate was filtered, washed with acetone (200 mL), and dried under vacuum to give crude compound (I) as the HCl salt. The resulting solid was dissolved in water (10 mL) and eluted with NaHCO 3 .₃The mixture was basified to pH 8 with a saturated solution of Na and extracted with 10% MeOH in DCM (5 x 100 mL).₂SO₄The crude residue was stirred in EtOH (10 mL). The crude product was solubilized in EtOH and after stirring for 1-2 hours, precipitation was again observed. The resulting precipitate was filtered and washed with EtOH (10 mL). The precipitate thus obtained was stirred again in EtOH (10 mL), filtered, subsequently washed with 2% MeOH in DCM (15 mL) and dried under vacuum to give 2-amino-1-(6-(2-amino-5-(3-methylpyridin-4-yl)-1H-imidazol-4-yl)-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)-2-methylpropan-1-one (compound (I)) as a pale yellow fluffy solid. Yield: 3.5 g, 44% (98.3% by LCMS). CHNOS MS (ESI+) m/z 392.8 [M+H]⁺.¹H NMR (400 MHz, DMSO-d₆+ d-TFA ): δ 8.78-8.84 (m, 2H), 7.93 (d, J = 6.1 Hz, 1 H), 7.44 (d, J = 2.1 Hz, 1 H), 7.09 (dd, J = 2.1, 8.6 Hz, 1 H), 6.97 (d, J = 8.6 Hz, 1 H), 4.34 (bs, 2H), 3.97 (bs, 2H), 2.16 (s, 3H), 1.60 (s, 6H).

Preferably, step 5B is selected.

Those skilled in the art will appreciate that pharmaceutically acceptable salts, hydrates, solvates, complexes, or prodrugs of compound (I) can be readily synthesized, typically using any of the syntheses disclosed herein, with known additional steps required to form compound (I) and then form a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.

The present invention will now be described with reference to specific examples. These are merely exemplary and for illustrative purposes only; they are not intended to limit in any way the scope of the claimed exclusivity or the described invention. These examples constitute the best mode presently contemplated for practicing the invention.

Comparative compound (II):

was synthesized by a method corresponding to synthetic route 1 described in WO2019/086890. Comparative compound (II) can also be synthesized by modifying the method outlined above for compound (I). Such modifications include the selection of an appropriate pyridyl starting material and the use of glycine as the amino acid.

Comparative compound (III):

was synthesized by a method corresponding to synthetic route 1 described in WO2019/086890. Comparative compound (III) can also be synthesized by modifying the method outlined above for compound (I). Such modifications include the selection of an appropriate pyridyl starting material and the use of glycine as the amino acid.

Compound (I) and comparative compounds (II) and (III) were subjected to the following analysis regarding minimum inhibitory concentration (MIC) and minimum inhibitory concentration 90 value (MIC ₉₀ ).

Minimum inhibitory concentrations (MICs) against antimicrobial-susceptible Escherichia coli (NCTC 13441) and Klebsiella pneumoniae (NCTC 13438) (planktonic bacteria) were determined by a broth microdilution procedure following the guidelines of the Clinical and Laboratory Standards Institute (Clinical and Laboratory Standards Institute. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard-Eleventh Edition, CLSI document M07, 11 January 2018). The broth dilution method involved two-fold serial dilutions of compounds in 96-well microtiter plates, resulting in a final concentration range of 0.39–200 μM, with a maximum final concentration of 2% DMSO. The bacterial strains tested were Escherichia coli (NCTC 13441) and Klebsiella pneumoniae (NCTC 13438). Strains were grown on cation-adjusted Mueller-Hinton broth or Luria-Bertani agar at 37°C in ambient atmosphere. The MIC (μM) was determined as the lowest concentration of compound that inhibited growth after a 20-24 hour incubation period. The results are shown in Table 1.

Using the methodology outlined above, the minimum inhibitory concentrations (MICs) for compound (I) and comparative compounds (II) and (III) against Proteus mirabilis (DSM 4479) were determined. The results are shown in Table 2. Compound (I) exhibits superior potency relative to comparative compounds (II) and (III).

The minimum inhibitory concentrations ( _MIC90 ) for 100 isolates of Escherichia coli and Klebsiella pneumoniae were determined. The minimum inhibitory concentrations ( _MIC90 ) required to inhibit 90% of the isolates (strains) were determined by broth microdilution according to the EUCAST susceptibility testing criteria (www.eucast.org). Bacterial inocula were prepared at approximately 1 x 10^6 CFU/mL by diluting a 0.5 McFarland suspension 1:100. An antimicrobial panel containing 50 μl of twice the final concentration of antimicrobial solution was diluted 2-fold with 50 μl of inoculum to obtain a final inoculum of approximately 5 x 10^5 CFU/mL and the desired test concentrations of antimicrobial agents (0.03-64 μg/mL). Plates were incubated according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI document M07, 11 January 2018, Clinical and Laboratory Standards Institute. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard—Eleventh Edition). _{The MIC} (μg/ml) is the MIC value at which 90% or more of the isolates (strains) in the test population are inhibited. The results are shown in Table 3.

Using the methodology outlined above for 100 isolates of Escherichia coli and Klebsiella pneumoniae, the minimum inhibitory concentrations (MICs) versus Proteus spp. and Providencia spp. were determined for Compound (I) and Comparative Compound (III). The results are shown in Table 4. Compound (I) exhibits superior potency relative to Comparative Compound (III).

Compound (I) and comparative compounds (II) and (III) were subjected to the following analyses regarding lipophilicity and volume of distribution (Vss).

The Log P values of lipophilic Compound (I) and Comparative Compound (III) were measured by performing an acid-based titration using a Sirius T3 instrument manufactured by Sirius Analytical to measure the pKa shift when the sample solution came into contact with an immiscible solvent (octanol). The Log P of Comparative Compound (II) was calculated using Marvin (physical and chemical calculation software). The results are shown in Table 5. The lipophilicity data of Compound (I) and Comparative Compounds (II) and (III) were collected in separate experiments performed on different days and are compared in Table 5.

The volume of distribution (Vss) of Compound (I) and comparative compounds (II) and (III) was determined from analysis of plasma concentration-time profiles obtained from rodent species (mice) after an IV bolus dose of 5 mg/kg, respectively. The volume of distribution was obtained by analyzing the rodent plasma profiles of Compound (I) and comparative compounds (II) and (III) using a two-compartment IV bolus model in PK Solver (Excel). The output Vss values are shown in Table 6. The amount of distribution data for Compound (I) and comparative compound (II) was collected in separate experiments performed on different days and is compared in Table 6.

Discussion of the Results Without being bound by theory, the inventors believe that the above results regarding lipophilicity and volume of distribution demonstrate that compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof can be advantageously used to treat infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus, particularly for the treatment of multi-site infections caused by gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus. The inventors believe that the above results demonstrate that compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof has the ability to effectively distribute to all sites of infection around a subject's body at sufficient concentrations to allow effective treatment at all sites. As well as ensuring that sufficient amounts of compound are available to exert a pharmacological effect, a balance must be maintained between ensuring that distribution of the compound from the plasma is fast enough to allow the drug to act quickly against the infection, and avoiding a very rapid release that would prevent the drug from reaching all possible sites of infection in sufficient concentrations.

Such a balance is believed to be demonstrated by the above results, which are discussed in more detail below.

The LogP value of a compound provides an indication of polarity and therefore the ability of the compound to reach the target tissue of a subject, i.e., the ease with which the drug can cross membrane barriers and distribute to possible intracellular infection sites around the subject's body.

Table 5 shows that compound (I) of the present invention has a higher Log P value, and therefore a lower polarity, compared to both comparative compounds (II) and (III), indicating improved tissue distribution of compound (I) compared to the more polar comparative compounds (II) and (III). The inventors believe that this improved tissue distribution of compound (I) allows enough drug to reach each of the infection sites to enable treatment, allowing the compound to distribute to all possible infection sites around the subject's body. As seen for comparative compounds (II) and (III) based on the Log P values in Table 5, ineffective drug distribution would result in insufficient drug concentrations throughout the infection sites, preventing treatment of the infection. As discussed above, there is a balance to be achieved regarding the efficiency with which the drug distributes around the subject's body. The Log P value of compound (I) indicates that compound (I) distributes to multiple infection sites and provides adequate drug concentrations at all of these infection sites, relative to comparative compounds (II) and (III).

The volume of distribution (Vss) provides an indication of the extent to which a compound distributes into the body tissues of a subject rather than into the plasma, i.e., the tendency of a compound to leave the plasma and distribute into the body tissues of a subject.

Table 6 shows that compound (I) has surprising and unexpectedly superior tissue penetration properties compared to comparative compounds (II) and (III), both of which are structurally very similar to compound (I).

The inventors have concluded that compound (I) exhibits good permeability. The lipophilicity and permeability of compound (I) enable the compound to reach and penetrate target tissues of interest. The surprising and unexpectedly superior tissue distribution and penetration properties of compound (I) versus comparative compounds (II) and (III) are attributable to the favorable lipophilicity and permeability of compound (I).

In vitro safety pharmacology studies were performed on Compound (I), Comparative Compound (II), and Comparative Compound (III) to evaluate the percentage of inhibition of 44 ligands (including receptors, transporters, ion channels, enzymes, and kinases) at a concentration of 10 μM. Compound binding was calculated as the percentage of inhibition of the binding of radiolabeled ligands specific to each target. Results showing greater than 50% inhibition were considered to represent a discernible effect of Compound (I), Comparative Compound (II), or Comparative Compound (III). Results for all 44 ligands tested are shown in Figures 1a, 1b, and 1c, while Figure 1d shows only results showing greater than 50% inhibition. In vitro pharmacological binding assays for Compound (I) and Comparative Compounds (II) and (III) were performed separately on different days and are compared in Figures 1a, 1b, 1c, and 1d.

Figures 1a, 1b, 1c, and 1d show that compound (I) has a different CEREP profile than both comparative compounds (II) and (III). Compound (I) exhibited greater than 50% inhibition against only a single ligand, i.e., fewer (and different) ligands than comparative compounds (II) and/or (III).

Proof-of-Concept Study Compound (I) and comparative compound (III) were evaluated in a proof-of-concept study in mouse models for the treatment of respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale, bacteremia or bloodstream infections caused by Gram-negative bacteria of the order Enterobacteriale, and urinary tract infections caused by Gram-negative bacteria of the order Enterobacteriale. The results are shown in Figures 2, 3, and 4a-c. Each dot, triangle, or square indicator represents one mouse. LOD refers to the limit of detection of bacteria. Stasis indicates the level of bacteria (colony forming units (CFU)) in the subject before treatment. Each proof-of-concept study was performed separately. Vehicle refers to a pharmaceutically acceptable carrier or excipient.

In a proof-of-concept study for the treatment of respiratory infections caused by or exacerbated by Gram-negative bacteria of the order Enterobacteriaceae, CD-1 mice were infected with Klebsiella pneumoniae ATCC 43816. Two hours after infection ("Pretreatment" in Figure 2), vehicle (20% hydroxypropyl β-cyclodextrin) containing no Compound (I) or Comparative Compound (III), or vehicle (20% hydroxypropyl β-cyclodextrin) containing Compound (I) or Comparative Compound (III) was administered by IV bolus at 20 mg/kg TID (8-hour intervals) for 1 day.

Figure 2 shows that at the end of the study (26 hours after initial infection; "Compound (I)" and "Comparative Compound (III)" in Figure 2), Compound (I) unexpectedly significantly reduced colony-forming units (CFU) compared to Comparative Compound (III), i.e., bacterial burden was significantly reduced by treatment with Compound (I) versus Comparative Compound (III) compared to pretreatment and vehicle. In fact, the CFU values for Comparative Compound (III) in Figure 2 remained relatively close to static levels, i.e., instances where no bacterial killing occurred. Figure 2 shows that at the end of the study (26 hours after initial infection), Compound (I) reduced bacterial burden in the lungs by 6.24 log compared to vehicle, while Comparative Compound (III) only showed a 4.16 log reduction compared to vehicle. Thus, compound (I) is 2 log more effective than comparative compound (III) in treating respiratory infections caused by Klebsiella pneumonia, particularly multidrug-resistant Klebsiella pneumonia.

In a proof-of-concept study for the treatment of bacteremia or bloodstream infections caused by Gram-negative Enterobacteriaceae bacteria, CD-1 mice were infected with human urine isolate Escherichia coli (E. coli) BAA-2469 (NDM-1 positive). One hour after infection ("Pretreatment" in Figure 3), vehicle (20% hydroxypropyl β-cyclodextrin) containing no compound (I) or comparative compound (III), or vehicle (20% hydroxypropyl β-cyclodextrin) containing compound (I) or comparative compound (III), was administered as a single IV bolus dose at 20 mg/kg.

Figure 3 shows that at the end of the study (9 hours after initial infection; "Compound (I)" and "Comparative Compound (III)" in Figure 3), Compound (I) unexpectedly significantly reduced colony-forming units (CFU) compared to Comparative Compound (III), i.e., bacterial load was significantly reduced by treatment with Compound (I) versus Comparative Compound (III) compared to pretreatment and vehicle. In fact, the CFU values for Comparative Compound (III) in Figure 3 remained above static levels, i.e., instances where bacterial killing did not occur. Figure 3 shows that at the end of the study (9 hours after initial infection), Compound (I) reduced blood bacterial load to below the limit of detection (LOD), a 7.43 log reduction compared to vehicle. In contrast, Comparative Compound (III) showed only a 4.86 log reduction compared to vehicle. Thus, compound (I) is 2.5 log more effective than comparative compound (III) in treating bacteremia or bloodstream infections caused by Escherichia coli, particularly multidrug-resistant Escherichia coli.

In a proof-of-concept study on the treatment of urinary tract infections caused by Enterobacteriaceae bacteria, female C3H/HeN mice were infected with Escherichia coli (E. coli) UTI89. Twenty-four hours after infection ("Pretreatment" in Figures 4a-c), vehicle (20% hydroxypropyl β-cyclodextrin) containing no compound (I) or comparative compound (III), or vehicle (20% hydroxypropyl β-cyclodextrin) containing compound (I) or comparative compound (III) was administered by IV bolus at 20 mg/kg TID (8-hour intervals) for 3 days.

Because urinary tract infections can affect the bladder and kidneys, bacterial burden was assessed in the urine, bladder, and kidneys (Figures 4a-c, respectively). Figures 4a and 4b show that at the end of the study (96 hours after initial infection; "Compound (I)" and "Comparative Compound (III)" in Figures 4a and 4b), Compound (I) unexpectedly had a significant reduction in colony-forming units (CFU) compared to Comparative Compound (III), i.e., bacterial burden was significantly reduced by treatment with Compound (I) versus Comparative Compound (III) compared to pretreatment and vehicle. Figure 4c shows that at the end of the study (96 hours after initial infection; "Compound (I)" and "Comparative Compound (III)" in Figure 4c), Compound (I) also had a significant reduction in colony-forming units (CFU) compared to Comparative Compound (III), i.e., bacterial burden was significantly reduced by treatment with Compound (I) versus Comparative Compound (III) compared to pretreatment and vehicle. Figure 4a shows that at the end of the study (96 hours after initial infection), compound (I) reduced the bacterial load in the urine below the limit of detection (LOD), a 6.59 log reduction compared to vehicle. In contrast, comparative compound (III) showed only a 3.36 log reduction compared to vehicle. Thus, compound (I) is 3 log more effective than comparative compound (III) in reducing CFU in urine, thus promoting the treatment of Escherichia coli urinary tract infections (UTIs). Figure 4b shows that at the end of the study (96 hours after initial infection), compound (I) reduced the bacterial load in the bladder by 5.67 log compared to vehicle. In comparison, comparative compound (III) showed only a 3.71 log reduction compared to vehicle. Thus, compound (I) is 3 log more effective than comparator compound (III) in reducing CFUs in the bladder, thereby facilitating the treatment of Escherichia coli urinary tract infections (UTIs). Figure 4c shows that at the end of the study (96 hours after initial infection), compound (I) reduced bacterial burden in the kidneys by 4.73 log compared to vehicle.

Compound (I) was further evaluated in proof-of-concept studies in mouse models for the treatment of respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and urinary tract infections caused by Gram-negative bacteria of the order Enterobacteriale. The results are shown in Figures 5 and 6a-c. Each dot, triangle, or square indicator represents one mouse. LOD refers to the limit of bacterial detection. Stasis indicates the level of bacteria (colony-forming units (CFU)) in the subject before treatment. Each proof-of-concept study was performed separately. Vehicle refers to a pharmaceutically acceptable excipient or carrier.

For further proof-of-concept studies on the treatment of respiratory infections caused or exacerbated by Gram-negative bacteria of the order Enterobacteriaceae, male CD-1 mice were infected with Klebsiella pneumoniae ATCC 43816.

Two hours after infection ("Pretreatment" in Figure 5), mice were treated with either a vehicle control (phosphate buffer) without compound (I) or a vehicle (phosphate buffer) containing compound (I) administered at a dose of 20 mg/kg via a 1-hour (QD) intravenous infusion. Mice receiving the vehicle control without compound (I) and some mice receiving the vehicle containing compound (I) received an additional 1-hour continuous intravenous infusion (BID, 3-hour intervals) 3 hours after the start of the first dose.

Figure 5 shows that at the end of the study (26 hours after initial infection; "Compound (I) QD" and "Compound (I) BID" in Figure 5), Compound (I) reduced colony-forming units (CFU), i.e., bacterial burden, with Compound (I) treatment compared to pretreatment and vehicle ("Vehicle BID" in Figure 5). This was particularly evident when Compound (I) was administered twice (BID, 3 hours apart) (P<0.0001 compared to both pretreatment and vehicle). For Compound (I) administered once (QD), the P was 0.0042 compared to pretreatment and <0.0001 compared to vehicle. Figure 5 shows that at the end of the study (26 hours after initial infection), Compound (I) reduced the bacterial burden in the lungs by 4.35 and 5.20 log compared to vehicle (one dose (QD) and two doses (BID, 3 hours apart), respectively), and by 0.95 and 1.80 log compared to pre-treatment (resting levels) (one dose (QD) and two doses (BID, 3 hours apart), respectively). Thus, Compound (I) is effective in treating respiratory infections caused by Klebsiella pneumoniae, particularly multidrug-resistant Klebsiella pneumoniae.

To further demonstrate the efficacy of Enterobacteriaceae in treating urinary tract infections, female C3H/HeN mice were infected with E. coli UTI89.

Twenty-four hours after infection ("Pretreatment" in Figures 6a-c), mice were treated with either a vehicle control (20% hydroxypropyl β-cyclodextrin) without Compound (I) or a vehicle (20% hydroxypropyl β-cyclodextrin) containing Compound (I) administered at a dose of 20 mg/kg via a 1-hour (QD) intravenous infusion. Some mice receiving the vehicle containing Compound (I) received an additional 1-hour continuous intravenous infusion (BID, 5-hour intervals) 5 hours after the start of the first dose. Dosing was continued once or twice daily for 3 days. For QD administration, administration occurred between 24-25, 48-49, and 72-73 hours postinfection. For BID administration, administration occurred between 24-25, 29-30, 48-49, 53-54, 72-73, and 77-78 hours postinfection.

Because urinary tract infections can affect the bladder and kidneys, bacterial burdens were assessed in the urine, bladder, and kidneys, respectively (Figures 6a-c). Figures 6a, 6b, and 6c show that at the end of the study (96 hours after initial infection; "Compound (I) QD" and "Compound (I) BID" in Figures 6a, 6b, and 6c), Compound (I) significantly reduced colony-forming units (CFUs), i.e., treatment with Compound (I) significantly reduced bacterial burden compared to pretreatment and vehicle. This was particularly evident when Compound (I) was administered twice daily (BID, 5 hours apart). Figure 6a shows that at the end of the study (96 hours after initial infection), both QD and BID daily administration of Compound (I) reduced bacterial burden in urine below the limit of detection (LOD), resulting in a 4.86 and 5.87 log reduction (for once-daily (QD) and twice-daily (BID, 5 hours apart), respectively) compared to vehicle. The P value for Compound (I) was <0.0001 compared to vehicle, regardless of whether it was administered once (QD) or twice-daily (BID, 5 hours apart). Thus, Compound (I) is effective in reducing CFU in urine, thus facilitating the treatment of Escherichia coli urinary tract infections (UTIs). Figure 6b shows that at the end of the study (96 hours after initial infection), both QD and BID daily administration of Compound (I) reduced the bacterial burden in the bladder to below the limit of detection (LOD), with a 5.01 and 5.84 log reduction (for once-daily (QD) and twice-daily (BID, 5 hours apart), respectively) compared to vehicle. The P value for once-daily administration (QD) was 0.001 and for twice-daily administration (BID, 5 hours apart) was 0.0002 compared to vehicle. Thus, Compound (I) is effective in reducing CFU in the bladder, thereby facilitating the treatment of Escherichia coli urinary tract infections (UTIs). Figure 6c shows that at the end of the study (96 hours after initial infection), Compound (I) reduced the bacterial burden in the kidney to below the limit of detection (LOD) when administered BID, with a 3.17-log reduction and a 4.3-log reduction (for once-daily (QD) and twice-daily (BID, 5-hour intervals), respectively) compared to vehicle. Compared to vehicle, the P value for once-daily (QD) administration was 0.0007 and for twice-daily (BID, 5-hour intervals) administration was <0.0001. Thus, Compound (I) is effective in reducing CFU in the kidney, thereby facilitating the treatment of Escherichia coli urinary tract infections (UTIs).

The present invention can provide the following aspects.
[1]
Compound (I):
or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.
[2]
The compound according to [1], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, for use in the treatment or prevention of infection with, or a disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus.
[3]
Compound (I) according to [1], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, for use in a method for treating infections caused by Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus, or diseases caused or exacerbated thereby.
[4]
Compound (I) according to [1], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, for the manufacture of a medicament for use in the treatment of infection with, or a disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus.
[5]
Compound (I) according to [1], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, for use in treating infections caused by Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus, or diseases caused or exacerbated thereby.
[6]
A method for treating an infection caused by, or a disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus in a subject in need thereof, comprising administering to the subject an effective amount of compound (I) according to [1], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.
[7]
The infection with, or disease caused or exacerbated by, gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus is selected from the group consisting of: bacteremia or bloodstream infection with gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus; respiratory infection with gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus; and/or a disease caused by or exacerbated by Gram-negative bacteria of the order Enterobacteriale, pyelonephritis caused by Gram-negative bacteria of the genus Haemophilus, and/or an intraperitoneal infection caused by Gram-negative bacteria of the order Enterobacteriale and/or a Gram-negative bacteria of the genus Haemophilus, preferably the infection caused by or the disease caused or exacerbated by Gram-negative bacteria of the order Enterobacteriale and/or a Gram-negative bacteria of the genus Haemophilus is one or more of the following: urinary tract infection (UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or a Gram-negative bacteria of the genus Haemophilus; bacteremia or bloodstream infection caused by Gram-negative bacteria and/or Gram-negative bacteria of the genus Haemophilus, respiratory infection caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and urinary tract infection (UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, more preferably one or more of the aforementioned caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus. The compound (I) according to any one of [2] to [5], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, or the method according to [6], wherein the infection, or the disease caused or exacerbated thereby, is one or more of the following: a respiratory infection caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus, and a urinary tract infection (UTI) caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus.
[8]
The compound (I) according to any one of [2] to [5] or [7], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, or the method according to [6] or [7], wherein the infection caused by, or the disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus is a multisite infection.
[9]
[0023] Compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof according to any of [2] to [5], [7], or [8], or the method according to any of [6] to [8], wherein compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is administered parenterally, preferably intravenously, more preferably by intravenous infusion (IV infusion).
[10]
The compound (I) according to any one of [2] to [5] and [7] to [9], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, or the method according to any one of [6] to [9], wherein the Gram-negative bacterium of the order Enterobacteriale and/or the Gram-negative bacterium of the genus Haemophilus is a carbapenem-resistant Enterobacteriale bacterium or an extended-spectrum β-lactamase Enterobacteriale bacterium.
[11]
The compound (I) according to any one of [2] to [5] and [7] to [10], or a pharmaceutically acceptable salt, hydrate, solvate, complex or prodrug thereof, or the method according to any one of [6] to [10], wherein the Gram-negative bacterium is of the order Enterobacteriaceae.
[12]
The Gram-negative bacteria of the order Enterobacteriale are selected from the group consisting of Arsenophonus, Atlantibacter, Biostraticola, Brenneria, Buchnera, Budvicia, Buttiauxella, Cedecea, Chania, Citrobacter, Cosenzaea, Cronobacter, Zyga ... Dickeya, Edwardsiella, Enterobacillus, Enterobacter, Erwinia, Escherichia, Ewingella, Franconibacter, Gibbsiella, Hafnia, Izhakiella, Kosakonia, Klebsiella, Kleibella, Kleibella uyvera), Leclercia, Lelliottia, Leminorella, Levinea, Lonsdalea, Mangrovibacter, Moellerella, Morganella, Obesumbacterium, Pantoea, Pectobacterium, Phaseolibacter, Photorhabdus, Plesiomonas, Pluralibacter, Pragia, Proteus, Providencia, Pseudocitrobacter, Rahnella, Raoultella, Rosenbergiella, Rouxiella, Saccharobacter, Salmonella monella, Samsonia, Serratia, Shigella, Shimwellia, Siccibacter, Sodalis, Tatumella, Thorsellia, Trabulsiella, Wigglesworthia, Xenorhabdus, Yersinia and Yokenella, preferably The gram-negative bacteria of the order Enterobacteriaceae include Cedecea, Citrobacter, Erwinia, Escherichia, Enterobacter, Klebsiella, Kluyvera, Plesiomonas, Proteus, Providencia, Raoultella, Salmonella, Serratia, Preferably, said Gram-negative bacterium of the order Enterobacteriale is selected from Erwinia, Escherichia, Enterobacter, Klebsiella, Proteus, Salmonella, Serratia, Shigella, and Yersinia, and preferably, said Gram-negative bacterium of the order Enterobacteriale is selected from Erwinia, Escherichia, Enterobacter, Klebsiella, Proteus, Salmonella, Serratia, Shigella, and Yersinia. The compound (I) according to any one of [2] to [5] and [7] to [11], or a pharmaceutically acceptable salt, hydrate, solvate, complex or prodrug thereof, or the method according to any one of [6] to [11], wherein the Gram-negative bacterium of the order Enterobacteriale is selected from the bacterial genera Enterobacter, Escherichia, and Klebsiella, more preferably the Gram-negative bacterium of the order Enterobacteriale is selected from the bacterial genera Escherichia and Klebsiella.
[13]
The compound (I) according to any one of [2] to [5] and [7] to [12], or the method according to any one of [6] to [12], wherein the Gram-negative bacterium of the order Enterobacteriaceae is selected from Enterobacter spp., Escherichia coli, and Klebsiella pneumoniae, more preferably Escherichia coli and Klebsiella pneumoniae.
[14]
A method for inhibiting the growth of Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus in vitro, using compound (I) according to [1] or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.
[15]
Compound (I), formulated together with a pharmaceutically acceptable excipient or carrier:
or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof.
[16]
A pharmaceutical composition comprising compound (I) according to [1], or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, and a pharmaceutically acceptable excipient or carrier.
[17]
[15] Compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex or prodrug thereof, according to [15], or the pharmaceutical composition according to [16], wherein the pharmaceutically acceptable excipient or carrier is a pharmaceutically acceptable excipient or carrier suitable for intravenous infusion into a human subject.
[18]
The compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is present in an amount of 50 to 6000 mg, preferably 50 to 4000 mg, for example 50 to 3000 mg, for example 50 to 2000 mg, for example 100 to 2000 mg, for example 200 to 2000 mg, for example 200 to 1750 mg, for example 200 to 1500 mg, for example 250 to 1000 mg. [16] or [17]. The pharmaceutical composition according to.
[19]
A pharmaceutical composition for use in treating infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus, comprising compound (I) according to [1] or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, and a pharmaceutically acceptable excipient or carrier, the pharmaceutical composition being preferably administered to a human subject by intravenous infusion.
[20]
A pharmaceutical composition for use in treating infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriale and/or gram-negative bacteria of the genus Haemophilus, comprising compound (I) according to [1] or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, and a pharmaceutically acceptable excipient or carrier, wherein compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is administered to a human subject by intravenous infusion at a dose of 50 to 6,000 mg per day.
[21]
The pharmaceutical composition according to [19], wherein compound (I), or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof, is administered to a human subject at a dose of 50 to 6000 mg per day.
[22]
The compound (I) or a pharmaceutically acceptable salt, hydrate, solvate, complex, or prodrug thereof is administered to a human subject at a dose of 50 to 4000 mg per day, for example, 50 to 3000 mg per day, for example, 50 to 2000 mg per day, for example, 100 to 2000 mg per day, for example, 200 to 2000 mg per day, for example, 200 to 1750 mg per day, for example, 200 to 1500 mg per day, for example, 250 to 1000 mg per day. [19], [20], or [21]. The pharmaceutical composition according to.
[23]
The pharmaceutical composition according to any one of [20] to [22], which is administered to a human subject by intravenous infusion once daily, twice daily, or three times daily, preferably twice daily.
[24]
When administered twice a day, the administration is at intervals of 1 to 12 hours, for example, at intervals of 1 to 8 hours, or at intervals of 2 to 6 hours, or at intervals of 2 to 5 hours, or at intervals of 3 to 5 hours, or at intervals of 1 to 4 hours. [23] The pharmaceutical composition according to [23].
[25]
The pharmaceutical composition according to any one of [20] to [24], which is administered to a human subject by intravenous infusion and is for use in treating respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and urinary tract infections (UTI) (typically complicated UTI) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus.
[26]
[26] The pharmaceutical composition according to any one of [20] to [25], which is administered to a human subject by intravenous infusion, and wherein the treatment of infection with, or a disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus involves a treatment course of 1 to 10 days, for example, 1 to 7 days, or 1 to 5 days.

Claims (23)

Compound (I):

or a pharmaceutically acceptable salt thereof. 10. The compound of claim 1, or a pharmaceutically acceptable salt thereof, for use in the treatment or prevention of infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus . 10. The compound (I) according to claim 1, or a pharmaceutically acceptable salt thereof, for use in a method for treating infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus. 2. The compound (I) according to claim 1, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for use in the treatment of infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus. 10. The compound (I) according to claim 1, or a pharmaceutically acceptable salt thereof, for use in the treatment of infections caused by, or diseases caused or exacerbated by, gram-negative bacteria of the order Enterobacteriaceae and/or gram-negative bacteria of the genus Haemophilus . 6. The compound (I) according to any one of claims 2 to 5, or a pharmaceutically acceptable salt thereof, wherein the infection caused by, or disease caused or exacerbated by, a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus is one or more of the following: bacteremia or bloodstream infection caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus; a respiratory infection caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus; a urinary tract infection (UTI) caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus; pyelonephritis caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus; and an intraperitoneal infection caused by a gram-negative bacterium of the order Enterobacteriale and/or a gram-negative bacterium of the genus Haemophilus . 6. The compound (I) according to any one of claims 2 to 5, or a pharmaceutically acceptable salt thereof, wherein the infection with, or disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus is a multisite infection . 6. The compound (I), or a pharmaceutically acceptable salt thereof, according to any one of claims 2 to 5, wherein the compound (I), or a pharmaceutically acceptable salt thereof, is administered parenterally. 6. The compound (I) according to any one of claims 2 to 5, or a pharmaceutically acceptable salt thereof, wherein the Gram-negative bacterium of the order Enterobacteriale and/or the Gram-negative bacterium of the genus Haemophilus is a carbapenem-resistant Enterobacteriale bacterium or an extended-spectrum β-lactamase Enterobacteriale bacterium . 6. The compound (I) according to any one of claims 2 to 5, or a pharmaceutically acceptable salt thereof, wherein the Gram-negative bacterium is of the order Enterobacteriaceae. The Gram-negative bacteria of the order Enterobacteriale are selected from the group consisting of Arsenophonus, Atlantibacter, Biostraticola, Brenneria, Buchnera, Budvicia, Buttiauxella, Cedecea, Chania, Citrobacter, Cosenzaea, Cronobacter, Dickeya, Edwardsiella, Enterobacillus, and Enterobacter. bacter, Erwinia, Escherichia, Ewingella, Franconibacter, Gibbsiella, Hafnia, Izhakiella, Kosakonia, Klebsiella, Kluyvera, Leclercia, Lelliottia, Leminorella, Levinea, Lonsdalea, Mangrovibacter, Moellerella, Morganella Morganella, Obesumbacterium, Pantoea, Pectobacterium, Phaseolubacter, Photorhabdus, Plesiomonas, Pluralibacter, Pragia, Proteus, Providencia, Pseudocitrobacter, Rahnella, Raoultella, Rosenbergiella, Rouxiel 6. The compound (I) according to any one of claims 2 to 5, or a pharmaceutically acceptable salt thereof, selected from the group consisting of Saccharobacter, Salmonella, Samsonia, Serratia, Shigella, Shimwellia, Siccibacter, Sodalis, Tatumella, Thorsellia, Trabulsiella, Wigglesworthia, Xenorhabdus, Yersinia and Yokenella . 6. The compound (I) according to any one of claims 2 to 5, or a pharmaceutically acceptable salt thereof , wherein the Gram-negative bacterium of the order Enterobacteriaceae is selected from Enterobacter spp., Escherichia coli, and Klebsiella pneumoniae. 10. A method for inhibiting the growth of Gram-negative bacteria of the order Enterobacteriaceae and/or the genus Haemophilus in vitro using compound (I) of claim 1, or a pharmaceutically acceptable salt thereof. A pharmaceutical composition comprising the compound (I) of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient or carrier. 15. The pharmaceutical composition of claim 14 , wherein the compound (I), or a pharmaceutically acceptable salt thereof, is present in an amount of 50 to 6000 mg . 10. A pharmaceutical composition for use in the treatment of infections caused by, or diseases exacerbated by, Gram-negative bacteria of the order Enterobacteriaceae and/or Gram-negative bacteria of the genus Haemophilus, comprising compound (I) of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient or carrier. 1. A pharmaceutical composition for use in treating infections caused by, or diseases caused or exacerbated by, Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, comprising compound (I) of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient or carrier, wherein compound (I), or a pharmaceutically acceptable salt thereof, is administered to a human subject by intravenous infusion at a dose of 50 to 6000 mg per day. 17. The pharmaceutical composition of claim 16 , wherein the compound (I), or a pharmaceutically acceptable salt thereof, is administered to a human subject at a dose of 50 to 6000 mg per day. The pharmaceutical composition according to claim 16 , 17 or 18 , wherein the compound (I), or a pharmaceutically acceptable salt thereof, is administered to a human subject at a dose of 50 to 4000 mg per day. 19. The pharmaceutical composition of claim 17 or 18 , administered to a human subject by intravenous infusion once daily, twice daily, or three times daily. 21. The pharmaceutical composition of claim 20 , when administered twice daily, at intervals of 1 to 12 hours. 19. The pharmaceutical composition of claim 17 or 18, administered to a human subject by intravenous infusion, for use in treating respiratory infections caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram-negative bacteria of the genus Haemophilus, and urinary tract infections (UTI ) caused by Gram-negative bacteria of the order Enterobacteriale and/or Gram- negative bacteria of the genus Haemophilus. 19. The pharmaceutical composition according to claim 17 or 18, which is administered to a human subject by intravenous infusion, wherein said treatment of infection with, or a disease caused or exacerbated by, a Gram-negative bacterium of the order Enterobacteriaceae and/or a Gram-negative bacterium of the genus Haemophilus involves a course of treatment of 1 to 10 days .